Optical transceiver and optical connector

ABSTRACT

An optical connector fitted upon a tip end portion of an optical fiber ribbon and disposed to face an optical input and output terminators which are installed upon a substrate, and which optically connects between optical fibers of the optical fiber ribbon and each of the optical input and output terminators. The optical connector includes a block shaped connector main body which is disposed to face the optical input and output terminators. The connector main body includes a hollow optical fiber holding portion for holding mainly a coating portion of an optical fiber which is led generally in parallel with the surface of the substrate, a plurality of optical fiber apertures into which the tip end vicinity of the optical fibers are inserted and fixed and a concave spot for changing the optical axis comprising a reflective surface for changing the optical axis and formed in front of an exit of the optical fiber apertures, which causes the optical axis direction of the optical fiber to face the optical input and output terminators.

This is a divisional of application Ser. No. 10/554,513 filed Oct. 26,2005 which issued as U.S. Pat. No. 7,534,052 on May 19, 2009, which is aNational Stage Entry of PCT Application No. PCT/JP2004/006339, filedApr. 30, 2004, which claims priority of Japanese Patent ApplicationsNos. 2003-125378 and 2003-125915 both filed Apr. 30, 2003. The entiredisclosures of the prior applications are considered part of thedisclosure of the accompanying divisional application and are herebyincorporated by reference.

TECHNICAL FIELD

The present invention relates to an optical transceiver for installingan optical connector which is provided at the tip end of an opticalfiber to a circuit board upon which is installed an optical device(optical element), which may be a light emitting device and/or a lightreceiving device, while determining its position at a position at whichsaid optical device and said optical fiber can be optically connectedtogether; and to an optical connector which is fitted upon a tip endportion of an optical fiber, which is disposed so as to be face to facewith an optical input and output terminator which is directly orindirectly installed upon a circuit board, and which optically connectsbetween the optical fiber and the optical input and output terminator.

BACKGROUND ART

Nowadays, with an optical transceiver which is used in an optical localarea network (LAN) system or the like, generally there is used a methodof connection to an external optical fiber, in which the optical axis ofan optical chip module, such as a light emitting device such as asemiconductor laser or the like, or a photodiode or the like, is made toextend along the direction of the circuit board, and an opticalconnector is fitted upon the end portion of the circuit board or leadframe upon which these optical devices have been mounted.

As the ferrule of the optical connector which is used here, a per seknown single-core optical ferrule (for example a MU type or a SC type),or multi-core optical ferrule (for example a MT type or a MINI-MT type)may be used, and optical transceivers which utilize all of theseferrules are already standardized.

However, in recent years, along with the enhancement of the requirementsfor compound photoelectric circuits and consolidated photoelectricsubstrates, since, with an optical transceiver which uses this method ofconnection in which the substrate direction is used for the opticalaxis, there are various types of limitation upon the fitting positionfor the optical connector, the flexibility (freedom) for designing theoptical connection path and the circuit board is limited, andfurthermore the problem arises that it is not possible to reduce thesize of the substrate. As related documentation, Japanese PatentApplication, First Publication No. 6-278641 may be cited by way ofexample.

An object of the present invention is to provide an optical transceiverwhich is capable of reducing the size of the structure for fitting anoptical connector to a circuit board upon which an optical device isinstalled, and with which the optical connector can easily be fittedupon the circuit board and the flexibility of design for the fittingposition is enhanced, and with which, furthermore, positionaldetermination of the optical connector with respect to the opticaldevice is easy and moreover it is possible to maintain the positionaldetermination accuracy stably over a long time period.

On the other hand, with an electronic device which is connected to anoptical path, when constructing upon an internal circuit board anoptical transceiver which sends and receives optical signals between theoptical fibers which constitute the optical path, although generally anoptical transceiver which has been mounted in a module is utilized, thestructure of this type of optical transceiver is generally made byinstalling an optical device (this expression includes both a lightemitting device and a light receiving device) which constitutes anoptical input and output terminator between the optical fiber upon atransceiver substrate interior to the transceiver case so that thedirection of its optical axis becomes parallel to the circuit board (inother words, by arranging the optical device in the optical axisdirection of the optical fiber which is parallel to the circuit board).

By contrast to this, attention has been directed to an opticaltransceiver which has been mounted in a module by surface installationof an optical device. In this case, by contrast to the optical axisdirection of the optical fiber which is led parallel to the circuitboard, the optical axis direction of the optical device is vertical tothe circuit board, so that it is necessary to direct the optical axisdirection of the optical fiber towards the side of the optical device.

In order to do this, it has been contemplated to assemble an opticalconnector which is capable of changing the optical axis to the tip endof the optical fiber, and to arrange this optical connector over theoptical transceiver of the circuit board; but, in this case, it isnecessary to direct the optical axis direction of the optical fibertowards the optical device with high accuracy. Furthermore, it isnecessary to avoid interference between the optical connector and thewiring pattern and so on, and furthermore increase of compactness isbeing demanded. However, the situation is that there is hardly anyoptical connector of an appropriate structure to cater sufficiently toall these various demands.

Another object of the present invention is to provide an opticalconnector is to provide, as an optical connector which can opticallyconnect between an optical fiber which constitutes an optical path andan optical device which is directly or indirectly installed upon acircuit board, an optical connector which is capable of directing theoptical axis direction of the optical fiber towards the optical devicewith high accuracy, and with which, furthermore, reduction in size iseasy, and avoidance of interference with the wiring pattern and so on isalso easy.

DISCLOSURE OF THE INVENTION

The optical transceiver according to a first embodiment of the presentinvention includes: an optical device which is provided upon asubstrate; an optical connector which is connected to an optical fiber;and a connector holder, which is installed upon said substrate, foroptically connecting together said optical device and said opticalconnector so that they may be attached to one another and detached fromone another. Said connector holder includes an engagement means whichholds said optical connector in a position in which said optical deviceand said optical fiber are connected together. Said engagement meansincludes a construction which, when said optical connector is pressed intowards said substrate, holds said optical connector while biasing ittowards said substrate. In the state in which said optical connector isheld by said connector holder, said optical connector supports saidoptical fiber so that the optical axis of said optical fiber subtends afixed angle with respect to the optical axis of a light emitting surfaceand/or a light receiving surface of said optical device. And saidoptical connector comprises a mirror which forms an optical path whichoptically connects between said optical device and said optical fiber.

Said engagement means may comprise a structure which, when said opticalconnector is pushed in the direction along the optical axis of saidlight emitting surface and/or light receiving surface of said opticaldevice, holds said optical connector while biasing it towards saidsubstrate.

The optical transceiver according to another embodiment of the presentinvention includes: an optical device which is provided upon asubstrate; an optical connector which is connected to an optical fiber;a connector holder, which is installed upon said substrate, foroptically connecting together said optical device and said opticalconnector so that they may be attached to one another and detached fromone another; and a position determination means which is provided uponsaid substrate, and which includes an engagement portion which, in theposition in which said optical device and said optical fiber areoptically connected, engages with an engagement reception portion ofsaid optical connector. In the state in which said optical connector isheld by said connector holder, said optical connector supports saidoptical fiber so that the optical axis of said optical fiber subtends afixed angle with respect to the optical axis of a light emitting surfaceand/or a light receiving surface of said optical device. And saidoptical connector comprises a mirror which forms an optical path whichoptically connects between said optical device and said optical fiber.

Said connector holder may include an engagement means which holds saidoptical connector by said optical connector being pushed in towards saidsubstrate.

Said engagement means may include a plurality of pressing pieces whichare provided to said connector holder and which can be elasticallydeformed, with, by said optical connector being pressed in between saidplurality of pressing pieces, said plurality of pressing pieces pressingin said optical connector towards said substrate from two or moredirections.

Said pressing pieces may include: projecting portions for pressing whichhold said optical connector by sandwiching it between themselves andsaid substrate; and guiding slant surfaces which, when said opticalconnector is pressed into the space between said plurality of pressingpieces, deform elastically in a direction to extend said space, so thatsaid optical connector is pressed in between said projecting portionsfor pressing and said substrate.

According to the optical transceiver of the above described embodiments,it is possible to optically connect together the optical device which isinstalled upon the circuit board and the optical fiber which is slantingwith respect to the optical axis of this optical device via the opticalconnector, by installing the optical connector above the circuit boardby arranging to press the optical connector, which has been assembled tothe optical fiber tip end, towards the circuit board from above saidcircuit board, and by determining its position by the positiondetermination means. Since, by doing this, apart from the space in whichthe position determination means and the optical connector are arranged,there is almost no requirement to keep any working space upon thecircuit board which is needed for pressing in the optical connectortowards the position determination means, accordingly, in practice, itis possible to implement the position determination of the opticalconnector upon the circuit board in a small space. Due to this,moreover, no limitation is imposed upon the circuit design and the likeof the circuit board, and it is possible to enhance the flexibility forthe installation position of the optical device upon the circuit board.

Furthermore, by pressing the optical connector towards the opticaldevice which has been installed upon the circuit board (or towards amodule to which the optical device has been installed), merely bypressing the optical connector into the engagement means upon thecircuit board, the position of said optical connector is determined bythe position determination means at a position in which it can beoptically connected to the optical device; and, since it is held by saidengagement means so as to be pressed inwards towards the circuit board,the connection of the optical device upon the circuit board and theoptical fiber (the optical connector) can be performed extremely simply.Yet further, with the structure which employs said engagement means, ifthe structure is held by the engagement means by the optical axis of thelight emitting surface and/or the light receiving surface of the opticaldevice being slanted with respect to the circuit board, and by beingpushed in to the engagement means upon the circuit board by shifting theoptical connector along said optical axis, then the requirement forensuring any working space upon the circuit board which is necessary forpushing the optical connector towards the engagement means is almostcompletely eliminated, apart from the space in which the engagementmeans and the optical connector are disposed. Accordingly, in practicalterms, it is possible to implement holding of the optical connector uponthe circuit board in a small space. Due to this, no limitation incircuit design or the like of the circuit board is imposed, and it alsois possible to enhance the degree of flexibility for installing theoptical device upon the circuit board.

The optical connector according to another embodiment of the presentinvention is fitted upon the tip end portion of an optical fiber and isdisposed to face an optical input and output terminator which isinstalled directly or indirectly upon a substrate, and opticallyconnects between said optical fiber and said optical input and outputterminator. This optical connector includes a block shaped connectormain body which is disposed to face said optical input and outputterminator; and said connector main body includes: a hollow opticalfiber holding portion for holding mainly a coating portion of an opticalfiber which is led generally in parallel with the surface of thesubstrate; an optical fiber aperture into which the tip end vicinity ofsaid optical fiber is inserted and fixed; and a concave spot forchanging the optical axis comprising a reflective surface for changingthe optical axis and formed in front of an exit of said optical fiberaperture, which causes the optical axis direction of the optical fiberto face said optical input and output terminator.

Said hollow optical fiber holding portion may connect together anoptical fiber insertion aperture portion which opens in a directionparallel to the surface of said substrate, and an adhesive materialfilling aperture portion which opens in a direction orthogonal to thesurface of said substrate.

A transparent or semitransparent adhesive material may be charged intosaid concave spot for changing the optical axis, which is covered overby a fixed transparent plate.

Said optical fiber may be an optical fiber ribbon, and a plurality ofoptical fiber apertures may be provided corresponding to each(single-core) optical fiber of the optical fiber ribbon, and a positiondetermination section may be provided which determines the positions ofthe optical fibers, which are led through each of the optical fiberapertures.

Pin holes for position determination, into which are fitted positiondetermination pins for performing positional determination with saidsubstrate side, may be provided respectively at both sides of theconnector widthwise direction of said concave spot for changing theoptical axis of said connector main body.

Position determination pins, which fit into pin holes for positiondetermination opened in said substrate side, may be providedrespectively at both sides of the connector widthwise direction of saidconcave spot for changing the optical axis of said connector main body.

Since, according to the optical connector of the present invention, theoptical fiber aperture and the reflective surface for changing theoptical axis are provided upon a block shaped unitary component (theconnector main body), and the mutual positional relationship between theoptical fiber axis and the reflective surface for changing the opticalaxis is fixed at high accuracy, accordingly it is possible to implementoptical axis changing of the optical axis direction towards the side ofthe optical device with good accuracy. By doing this, it is possible toreduce the losses in the optical connection between the optical fiberand the optical device. Furthermore, since the optical fiber apertureand the reflective surface for changing the optical axis are providedupon the block shaped unitary component, it is easily possible toimplement reduction in size of the structure, and, moreover, it is alsoeasy to avoid interference with the wiring pattern and the like upon thecircuit board.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall perspective view showing the structure of anoptical transceiver according to the present invention.

FIG. 2 is a side view showing the optical transceiver of FIG. 1.

FIG. 3 is a side view of the optical transceiver of FIG. 1, as seen fromthe opposite side to that of FIG. 2.

FIG. 4 is an elevational sectional view of the optical transceiver ofFIG. 1.

FIGS. 5A through 5C are figures schematically showing an opticalconnector which is fitted to the optical transceiver of FIG. 1, whereinFIG. 5A is an elevational sectional view, FIG. 5B is an under surfaceview as seen from the side of a junction face which joins to a junctionface of an photoelectric conversion module, and FIG. 5C is a side view.

FIG. 6 is a side view of the optical connector of FIGS. 5A through 5C.

FIG. 7 is a perspective view (but a view as seen upside down) of theconnector main body of an optical connector of an embodiment of thepresent invention.

FIG. 8 is a plan view of the connector main body of FIG. 7.

FIG. 9 is an A-A sectional view of FIG. 8.

FIG. 10 is a B-B sectional view of FIG. 9, in the state in which aposition determination pin is fitted into a position determination pinhole.

FIG. 11 is a C-C sectional view of FIG. 9, in the state in which theposition determination pin is fitted into the position determination pinhole.

FIG. 12 is a view of FIG. 8, in the state in which the central line ofan optical fiber ribbon is fitted into the connector main body.

FIG. 13 is a sectional view of an optical connector of an embodiment ofthe present invention which has been built using the above describedconnector main body, shown in its state of use (in the state of FIG. 9,but reversed top and bottom).

FIG. 14 is an enlarged view of essential elements of FIG. 13.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to the drawings, preferred embodiments of the presentinvention will be explained hereinafter. However, the present inventionis not to be considered as being limited to the embodiments below; forexample, it would be acceptable appropriately to combine the variousstructural elements of these embodiments with one another, and it wouldbe acceptable to add or to substitute other per se known structures.

Embodiment 1

FIG. 1 is an overall perspective view showing the structure of anoptical transceiver 10 (an optical transceiver of the type which isinstalled upon a substrate) according to the present invention, whileFIG. 2 is a side view thereof (the side where a coated optical fiber 15comes out), FIG. 3 is a side view of the optical transceiver of FIG. 1from the opposite side to that of FIG. 2, and FIG. 4 is an elevationalsectional view thereof.

In FIGS. 1 through 4, the reference numeral 11 denotes a circuit board(a substrate), while 12 denotes a photoelectric conversion module, 13denotes a connector holder, 14 denotes an optical connector, and 15denotes a coated optical fiber (core wire). Although the coated opticalfiber of this embodiment is one in which a plurality of optical fibers15 a which are sheathed with plastic or the like are juxtaposed andbundled, the present invention is not limited to this.

The photoelectric conversion module 12 of this embodiment is a chip formor array form module in which there are mounted, as optical devices, aplurality of light emitting devices such as semiconductor lasers (forexample, laser diodes: LD) or the like, or light receiving devices suchas photodiodes (PD) or the like. The optical axis of said optical deviceof the photoelectric conversion module 12 (i.e. the axis which makes aright angle with its light receiving surface) is orthogonal with respectto the circuit board 11. This photoelectric conversion module 12 iselectrically connected to a circuit or the like upon the circuit board11. In FIG. 4, optical devices 16 of the photoelectric conversion module12 are formed on a surface (hereinafter referred to as a junction face12 b) of the photoelectric conversion module 12 opposite to its lowersurface 12 a which abuts upon the circuit board 11. This junction face12 b extends in the direction along the circuit board 11. Although it isnot particularly shown in the Figures, upon the circuit board to whichthis photoelectric conversion circuit is mounted, according torequirements, there may be mounted an photoelectric conversion circuit,a control processing section, an optical signal processing circuit, anoptical device drive circuit, a storage circuit, or, other than these,various circuitry or the like which performs drive control or the likeof electronic components upon the circuit board; or, again according torequirements, an LSI which is endowed with these circuit functions maybe mounted thereupon.

The optical transceiver 10 comprises the photoelectric conversion module12 which is installed upon the circuit board 11, and the frame shapedconnector holder 13 which is fixed upon the circuit board 11, and whichdescribes a rectangle which is arranged so as to surround saidphotoelectric conversion module 12 from its outside. This connectorholder 13 holds the optical connector 14 which is fixed at the tip endof the coated optical fiber 15 so as to fix its position over thephotoelectric conversion module 12, and serves the function of pressingit in so that it undergoes no positional deviation with respect to thephotoelectric conversion module 12. In this embodiment the coatedoptical fiber 15 and said optical devices 16 are optically connectedtogether, by a (below-mentioned) junction face 14 a of the opticalconnector 14, which is supported by the connector holder 13, beingconfronted with an optical axis in the vertical direction with respectto a junction face 12 b (in other words, in this embodiment, with anoptical axis which is almost orthogonal to the circuit board 11), and byoptically connecting it to the junction face 12 b of the photoelectricconversion modules 12.

The connector holder 13 of this embodiment is one which is made in a boxshape by bending a metallic plate which is made from stainless steel orthe like, and comprises fixing pieces 13 b which are provided so as toproject out from a plurality of locations of a contact section 13 a (thelower edge portion of a frame shaped main body 13 d) which is mountedupon the circuit board 11. These fixing pieces 13 b pass throughthrough-holes which are formed in the circuit board 11, and are fixed tothe circuit board 11 at the rear surface of said circuit board 11 (thesurface thereof which is at its bottom side in FIGS. 2 and 3). Due tothis, the connector holder is fixed to the circuit board 11 so as not towobble thereupon.

FIGS. 5A through 5C are figures showing the structure of the opticalconnector 14 in schematic form. FIG. 5A is a frontal sectional view;FIG. 5B is a bottom view as seen from the side of the junction face 14 awhich is joined to the junction face 12 b of the photoelectricconversion module 12; and FIG. 5C is a side view. And FIG. 6 is a sideview of this optical connector 14.

The optical connector 14 of this embodiment comprises a main body 14 bwhich is formed from plastic or the like in a rectangular plate shape,and a glass plate 14 c which is formed in a rectangular shape and whichis adhered to the central portion of the bottom surface of this mainbody 14 b; and, between the glass plate 14 c and the main body 14 b,there are sandwiched a plurality of optical fibers 15 a which areexposed from the end portion of the coated optical fiber 15. The lowersurface of the glass plate 14 c is coincident with the junction face 14a of the optical connector 14. When the optical connector 14 is arrangedso as to be superimposed over the photoelectric conversion module 12,the glass plate 14 c is arranged to confront the junction face 12 b ofthe photoelectric conversion module 12. The optical connector 14 isformed in a rectangular shape of almost the same size, or slightlysmaller than, as the photoelectric conversion module 12, so that, evenwhen it is positioned over the photoelectric conversion module 12, itdoes not greatly project from the photoelectric conversion module 12 tothe outside.

Instead of the glass plate 14 a, a transparent plate, which is made fromsome substance other than plate glass, can also be employed. Forexample, it would be acceptable to use one which is made from a plastic.Any transparent plate will be acceptable, provided that it is formedfrom a material for which no problems arise in practice with regard tooptical attenuation or occurrence of losses, at least for the wavebandwhich is to be used.

Each of the optical fibers 15 a which are sandwiched between the mainbody 14 b of the optical connector 14 and the glass plate 14 c isinserted into its one of position determination grooves 14 d formed inthe main body 14 b, so that their positions are accurately determined.These position determination grooves 14 d are formed at a pitch which isapproximately the same as the pitch at which the optical fibers 15 a arearranged in series, and they are formed in the same number as the numberof the optical fibers 15 a, or greater.

The optical fibers 15 a of this embodiment are single-core opticalfibers which are exposed from the tip end of the coated optical fiber15, which is a multi-core coated optical fiber ribbon. Between the mainbody 14 b of the optical connector 14 and the glass plate 14 c, theplurality of optical fibers 15 a which are exposed at the tip end of thecoated optical fiber 15 are arranged in a series parallel to one anotherby the plurality of position determination grooves 14 d formed in a lineparallel to one another upon the surface of the main body 14 b of theoptical connector upon which the glass plate 14 c is fitted, so that theposition of each of these optical fibers 15 a is accurately determined.This position determination is performed by a single one of the opticalfibers 15 a being received in a single one of the position determinationgrooves 14 d.

The cross sectional shape of the position determination grooves 14 d, inthis embodiment, is that of a V groove. However, the cross sectionalshape is not limited to this; it would also be acceptable for the crosssectional shape of the position determination grooves 14 d, for example,to be that of a round groove (a semicircular cross sectional shapedgroove), a U-shaped groove, or the like. Furthermore, instead of formingthe position determination grooves upon the lower surface of the mainbody 14 b of the optical connector 14, it would also be possible toutilize a structure in which they were formed upon the upper surface ofthe glass plate 14 c, or a structure in which they were formed both uponthe lower surface of the main body 14 b of the optical connector andalso upon the upper surface of the glass plate 14 c.

As for the coated optical fiber 15, this is not limited to themulti-core coated optical fiber ribbon shown in the Figures; forexample, it would also be acceptable to utilize a single-core coatedoptical fiber, or the like. Provided that it is possible to determinethe position of the optical axes of the optical fibers at high accuracywith respect to the reflective portion 14 g (described below), it willbe acceptable to determine the positions of the bare optical fibers, orof the coated optical fibers, or of the optical fiber base material, orthe like by the use of the position determination grooves. However, fromthe point of view of enhancing the accuracy of position determination,it is desirable for the portions which are held in the positiondetermination grooves to be bare optical fiber over their entirelengths, or for at least the tip end portions which are thus held to bebare optical fiber. In this case, for example, the portions other thanbare optical fiber at the tip ends may be coated optical fiber, or asingle-core fiber such as an optical fiber, or the like.

The position determination grooves need only to be formed so as to beable to determine the position at a sufficiently high accuracy, so thatthe desired orientation for the bare optical fibers in the opticalfibers 15 a with respect to a reflecting portion 14 g (described below)is obtained. For example, if the optical fibers 15 a have relativelythick coating portions, it will be acceptable to use, as the positiondetermination grooves, fine groove portions which receive the bareoptical fibers, and relatively thick groove portions for receiving saidcoating portions which are formed as extending from these fine grooveportions.

A concave spot 14 f, which is hollowed out more deeply than the surface14 e, is formed upon the lower surface of the main body 14 b of theoptical connector 14, at a position which corresponds to the tip ends ofthe optical fibers 15 a. The concave spot 14 f of this embodiment is agroove which is cut sideways across the main body 14 b in a directionorthogonal to the lengthwise direction of the optical fibers 15 a.

A reflective portion 14 g is formed in this concave spot 14 f upon theextensions of the optical axis of the tip end surfaces of the opticalfibers 15 a (specifically, of the bare optical fibers at their tip ends)which are inserted into the concave spot 14 f. A certain clearance isdefined between this reflective portion 14 g and the tip ends of theoptical fibers 15 a (specifically, of the bare optical fibers at theirtip ends).

This reflective portion 14 g is formed upon the inner wall surface ofthe concave spot 14 f by forming a metallic vapor deposition film or thelike. The reflective portion 14 g constitutes a reflective surface whichis slanted at an angle of 45 degrees with respect to the extension ofthe optical axis from the tip end surfaces of the optical fibers(specifically, of the bare optical fibers), and, when the opticalconnector 14 is attached upon the photoelectric conversion module 12, ispositioned above each of the optical devices 16 of the photoelectricconversion module 12, and confronts the light emitting surfaces or thelight receiving surfaces of the optical devices 16. Thus, thisreflective portion 14 g functions as a mirror, which bends a beam oflight emitted from the ends of the optical fibers 15 a (specifically,from the tip ends of the bare optical fibers) at 90 degrees and guidesthe light beam into the optical devices 16, or which bends a beam oflight emitted from the optical devices 16 at 90 degrees and guides thelight beam into the optical fibers 15 a. In other words, the reflectiveportion 14 g constitutes an optical path 17 between the optical fibers15 a and the optical devices 16.

On the optical path 17, a portion which is positioned between thereflective portion 14 g and the optical devices 16 is an optical pathwhich connects between the optical connector 14 and the optical devices16, and is slanted with respect to the circuit board 11 (in thisembodiment, it is almost orthogonal thereto). Due to this, with thisoptical transceiver 10, each of the optical devices 16 and itscorresponding one of the optical fibers 15 a are optically connectedtogether through an optical axis, which is slanted with respect to thecircuit board 11. This optical connector 14 carries out a function ofoptically connecting the optical fibers 15 a, which extend in thehorizontal direction with respect to the optical axis of the opticalpath connecting between the optical connector 14 and the optical devices16, to the optical devices 16.

Although, here, in concrete terms, said reflective portion whichfunctions as a mirror is a reflective layer which is formed by metallicfilm vapor deposition, this is not limitative; for example, it would beacceptable to form this reflective portion by fitting a chip upon whicha metallic layer had already been formed into the concave spot 14 f.Various other structures could also be employed.

The reflective portion 14 g is not restricted to being one which has areflective surface which is slanted at an angle of 45 degrees withrespect to the line of extension of the optical axis of the tip endsurface of the optical fiber (more exactly, of the bare optical fiber).Any reflective surface 14 g will be acceptable, provided that it is onewhich can form an optical path which is bent around between the tip endsof the optical fibers 15 a which are fixed in the optical connector 14and the optical devices 16, and that it is one which can opticallyconnect between the optical fibers 15 a which extend in the horizontaldirection with respect to the optical axis of the optical path whichconnects between the optical connector 14 and the optical devices 16,and the optical devices 16; and the slant angle of the reflectivesurface with respect to the prolongation of the optical axis of the tipend surface of the optical fiber (more exactly, of the bare opticalfiber) is not one which is particularly limited.

It is not absolutely necessary for the optical fibers 15 a to beprojected from the position determination grooves 14 d into the concavespot 14 f; it would also be acceptable for their tip end portions not toproject into the concave spot 14 f, provided that the accuracy ofpositional determination of their tip end portions which confront thereflective portion 14 g were maintained with respect to the reflectiveportion 14 g; and it would also be possible to utilize a structure inwhich they are positioned over the position determination grooves.

The junction face 14 a side of the concave spot 14 f is covered over bythe glass plate 14 c, so that, after the optical fibers 15 a have beenfixed, contamination due to the ingress of dust or dirt or the like canbe prevented. Although this concave spot 14 f may be a cavity, as in thesecond and the third embodiments to be described hereinafter, it mayalso be filled with a transparent adhesive material (217) (or atranslucent one which does not obstruct the optical path), so that theoptical fibers 15 a and the glass plate 14 c are fixed.

The light which follows the optical path 17 between the optical fibers15 a and the junction faces of the optical devices 16, and in particularthe light which passes between the reflective portion 14 g and thejunction faces of the optical devices 16, is arranged to be transmittedthrough the glass plate 14 c. This glass plate 14 c has the opticalcharacteristic of being able to pass the light which pursues the opticalpath 17 with the occurrence of hardly any losses due to scattering orthe like.

According to this optical transceiver 10, by positioning the opticalconnector 14 over the photoelectric conversion module 12, and by holdingit in the connector holder 13, it is possible to implement an opticalconnection between the optical devices 16 and the light path of thecoated optical fiber 15 (the light path which is formed by each of theoptical fibers 15 a).

Furthermore, the optical connector 14 which has been positioned on topof the photoelectric conversion module 12 is pressed into thephotoelectric conversion module 12 by the structure of the connectorholder 13, and is stably held thereby so that its position does notdeviate with respect to the photoelectric conversion module 12.

In detail, as shown in FIG. 2, the connector holder 13 comprises a pairof pressing pieces 13 c, which are elastic pieces for pressing in theoptical connector 14 against the photoelectric conversion module 12.These pressing pieces 13 c are small plate spring shaped pieces whichproject from the frame shaped main body 13 d of the connector holder 13so as to stand up therefrom, and function as engagement means. And thesepressing pieces 13 c comprise projecting portions for pressing 13 fwhich are formed to be sinuous, so as to slightly rise up from the frameshaped main body 13 d of the connector holder 13 to the inwards side asseen in the plane of said frame shaped main body 13 (in other words,towards the side of the space between the plurality of pressing pieces13 c, into which the optical connector 14 is pressed (the space 13 e forpressing in the optical connector)). These projecting portions forpressing 13 f are formed so as to intrude into the optical connectorpressing in space 13 e from the base end portions of the pressing pieces13 c which project from the connector holder 13.

In these projecting portions for pressing 13 f, from the spot (theprojecting tip end 13 g) which is most projected inward towards thecentral portion of said optical connector pressing in space 13 e, theportion (the folded back portion 13 h) which is positioned at theprojecting tip end of the pressing pieces 13 c from the connector holder13 is slanted so that the height by which it rises up from the connectorholder 13 becomes higher according to progress from the projecting tipend 13 g of the projecting portion for pressing 13 f towards the outerside of the optical connector pressing in space 13 e, and there areformed guide slant surfaces 13 i which lead the optical connector 14which is pressed from above the connector holder 13 into said connectorholder 13 (in concrete terms, into the optical connector pressing inspace 13 e) into the optical connector pressing in space 13 e.

With this optical transceiver 10, the optical connector 14 is engagedwith the pressing pieces 13 c on both sides of the optical connectorpressing in space 13 e (in concrete terms, it is engaged with theprojecting portions 13 f for pressing) by confronting its junction face14 a towards the optical devices 16, and by moreover, while holding itjust as it is with said junction face 14 a in an attitude which isalmost parallel to the circuit board 11, pressing it into the opticalconnector pressing in space 13 e by applying pressure from above theconnector holder 13 towards the optical devices 16. By doing this, it ispossible for the optical connector 14 to be pressed in towards thecircuit board 11 by the plurality of pressing pieces 13 c, and it ispossible to hold it in the state of being pressed against thephotoelectric conversion module 12.

Furthermore, the accuracy of positional determination for the opticalconnector 14 with respect to the photoelectric conversion module 12 canbe maintained, due to the fact that a pair of position determinationpins 14 h which are projected from its junction face 14 a are insertedinto and engaged with pin holes 12 c which open upon the junction face12 b of the photoelectric conversion module 12. Although these positiondetermination pins 14 h are arranged on both sides of the reflectiveportion 14 g, or, to put it in another manner, so as mutually to opposeone another on both sides of the concave spot 14 f, the positions forarrangement of this pair of position determination pins 14 h are notlimited to this, but can be varied as may be appropriate.

These position determination pins 14 h function as positiondetermination means for determining the position of the opticalconnector 14 to a position in which it can optically connect withrespect to the optical device 16. However, since the insertion of theseposition determination pins 14 h into the pin holes 12 c is startedbefore the optical connector 14 is engaged to and held by the pressingpieces 13 c, accordingly, when the insertion of the positiondetermination pins 14 h into the pin holes 12 c is started by thepressing in of the optical connector 14 into the optical connectorpressing in space 13 e, the optical connector 14 is progressivelypressed into the optical connector pressing in space 13 e (or, to put itin another manner, into the engagement means which is constituted by theplurality of pressing pieces 13 c) towards the optical devices 16, dueto being shifted along the optical axes of the light emitting surfacesor the light receiving surfaces of the optical devices 16. And, when theoptical connector 14 engages to the plurality of pressing pieces 13 cwhich constitute the engagement means, and the optical connector 14 isheld by the engagement means so as to be pressed in towards the circuitboard 11, due to the accuracy of the position determination pins 14 hand the pin holes 12 c, the position of the optical connector 14 isdetermined at the high accuracy at which it can be optically connectedwith respect to the optical device 16.

The position determination pins are ones which correspond to the fittingtogether pins according to the present invention, and the positiondetermination pins which are fixed to the optical connector and thephotoelectric conversion module in which are formed the pin holes intowhich these position determination pins are inserted and fitted,together function as a position determination means of a pin fittingtogether type which determines the position of said optical connectorupon the circuit board to a position in which it can optically connectwith respect to the optical device.

Although, in this embodiment, a method has been shown by way of examplein which the fitting together pins (the position determination pins)which were provided as projecting on the side of the optical connectorwere inserted into and fitted together with the pin holes of thephotoelectric conversion module, the position in which the pin holes areformed is not necessarily the photoelectric conversion module; it wouldbe acceptable for it to be a member which is fixed to the circuit boardother than the photoelectric conversion module, or to be the circuitboard itself.

Furthermore, it would also be possible to utilize a method in whichfitting together pins which were provided as fixed to and projectingfrom a member which was fixed to the circuit board (the photoelectricconversion module or the like), or to the circuit board itself, werefitted together by being inserted into pin holes which were formed uponthe optical connector.

In concrete terms, the engagement and holding of the optical connector14 by the pressing pieces 13 c of the engagement means is implemented bythe projecting portions 14 i which are provided as projecting on bothopposite side portions of the optical connector 14 being sandwichedbetween the projecting portions for pressing 13 f of the pressing pieces13 c and the photoelectric conversion module 12. In other words, theoptical connector 14 is pressed against the photoelectric conversionmodule 12 by both of the pressing pieces 13 c. By the optical connector14 being sandwiched and squeezed between the projecting portions forpressing 13 f of the pressing pieces 13 c and the circuit board 11, itis pressed against the circuit board 11 by the projecting portions forpressing 13 f of the pressing pieces 13 c.

The dimension between the projecting portions 14 i on both opposite sideportions of said optical connector 14 (the dimension between theprojecting tip ends of the projecting portions 14 i from the opticalconnector 14) is somewhat greater than the separation distance betweenthe projecting tip ends 13 g of the projecting portions for pressing 13f of the pair of pressing pieces 13 c, so that, when the opticalconnector 14 which has been pressed from above the connector holder 13against the projecting portions for pressing 13 f of the pressing pieces13 c which constitute the engagement means (in concrete terms, againsttheir folded back portions 13 h) (in concrete terms, the projectingportions 14 i are pressed against the projecting portions for pressing13 f) is pressed inwards towards the optical devices 16, it is possibleto press in the optical connector 14 towards the optical devices 16while elastically deforming the pressing pieces 13 c so as to open outthe optical connector pressing in space 13 e, due to the slanting of theguiding slant surfaces 13 e of the folded back portions 13 h withrespect to the direction in which the optical connector 14 is beingpressed inwards. In other words, with regard to the pair of pressingpieces 13 c, the pressing in of the optical connector 14 into theoptical connector pressing in space 13 e towards the optical device 16progresses while pressing and opening out between this pair of pressingpieces 13 c. And, when the optical connector 14 (in concrete terms, itsprojecting portions 14 i) passes the projecting portions for pressing 13f of the pressing pieces 13 c towards the side of the photoelectricconversion module 12, the projecting portions 14 e on both the sides ofthe optical connector 14 are sandwiched between the photoelectricconversion module 12 and the projecting portions for pressing 13 f ofthe pressing pieces 13 c, so that the optical connector 14 is pressedinwards towards the photoelectric conversion module 12 by both thepressing pieces 13 c.

As for the pressing pieces, it will be acceptable for them to be elasticpieces which comprise projecting portions for pressing for holding theoptical connector so that it is sandwiched between them and the circuitboard, and guiding slant surfaces for implementing elastic deformationof said pressing pieces, in accompaniment with the pressing in of theoptical connector, in the direction to expand the optical connectorpressing in space 13 e (i.e. elastic deformation towards the exterior ofthe optical connector pressing in space 13 e), thus ensuring that theoptical connector is pressed in between said projecting portions forpressing and the circuit board; and their concrete form is not to beconsidered as being particularly limited. For example, instead of theplate spring shaped projecting portions for pressing which were formedas being sinuous, it would also be possible to utilize plate springshaped projecting portions for pressing which were formed as beingcurved. Furthermore, it would also be possible to utilize pressingpieces which consisted of members other than the connector holder, orpressing pieces made of a resin substance or the like.

The structure of the engagement means which presses the opticalconnector inward with respect to the photoelectric conversion module 12is not limited to being pressing pieces of the above described shape; itwould be possible to utilize various different types of structure, suchas, for example, a structure in which an engagement protuberance whichwas formed as projecting on the inner surface of the frame shaped mainbody 13 d and an engagement concavity which was formed upon the sidesurface of the optical connector 14 were engaged together, or the like.

According to the optical transceiver 10 described above, it is possibleto manage with a space for installation of the optical connector 14 uponthe circuit board 11 which is the same, or is somewhat greater than, thespace which is required for installation of the photoelectric conversionmodule 12 upon the circuit board 11, so that it is possible to implementthe connection between the photoelectric conversion module 12 (inconcrete terms, the optical devices 16) upon the circuit board 11 andthe coated optical fiber 15 in an extremely limited space.

The present invention is not limited to the embodiment described above;various modifications are possible.

Namely, in the embodiment described above, a structure was shown, by wayof example, in which the coated optical fiber 15 and the optical device16 were optically connected together via the optical connector 14 by theoptical connector 14 being optically connected to the optical device 16along an optical axis in a direction which was almost orthogonal withrespect to the circuit board 11. However, with the present invention,provided that the orientation of the optical axis along which theoptical device 16 and the optical connector 14 are connected together isa direction which is slanted with respect to the circuit board, it isnot limited to being a direction which is almost orthogonal with respectto the circuit board. To express it in another manner, the presentinvention is one which can optically connect, via an optical connector,an optical fiber which extends in a direction along a circuit board withrespect to an optical device which has an optical axis which has aslanting direction with respect to the circuit board, and, provided thatthe engagement means is one which can perform a function of holding theoptical connector while fixing its position at a position where opticalconnection of the optical fiber with respect to this type of opticaldevice is possible, it is possible to utilize various different concreteconstructions for the connector holder.

Although, in said embodiment, a structure was shown by way of example inwhich the optical connector was held by the connector holder and wasdisposed so as to be superimposed over the optical device 16 which wasinstalled upon the circuit board, the present invention is not limitedto this structure; for example, it would also be possible to utilize astructure in which an optical connector which was held and whoseposition was determined with respect to an optical device which wasinstalled upon one side surface of a circuit board by being pressedtowards the optical device by a connector holder upon the other sidesurface of the circuit board, was optically connected to the opticaldevice via a through hole in the circuit board.

Although the above described embodiment was an optical transceiver whichutilized an optical connector of a surface installed type which wasinstalled upon the circuit board, the optical transceiver of the presentinvention also includes a structure for fitting the optical connector inan attachable and detachable manner to a substrate which is not acircuit board. For example, the case in which only optical devices areprovided to the substrate, but no electrical circuitry, is also includedwithin the scope of the present invention. Furthermore, the substrateitself is not a structural requisite for the optical transceiver of thepresent invention; the optical transceiver of the present invention, atits minimum limit, only comprises an optical device, an opticalconnector, and a connector holder.

Embodiment 2

FIG. 7 is a perspective view showing a connector main body 22 of anoptical connector of the second embodiment as seen upside down, FIG. 8is a plan view thereof, FIG. 9 is an A-A sectional view of FIG. 8, FIG.10 is a B-B sectional view of FIG. 9, FIG. 11 is a C-C sectional view ofFIG. 9, FIG. 12 is a view of a state in which a coated optical fiberribbon has been inserted into the connector main body 22 of FIG. 8, FIG.13 is a sectional view showing a situation in which an optical connector21 which has been made using the above described connector main body 22is being used, and FIG. 14 is an enlarged view of an essential portionof FIG. 13.

The optical connector 21 of this embodiment, as shown in FIGS. 13 and14, is one for optically connecting together an optical fiber 32 whichconstitutes an optical path, and an optical device 25 of an opticaltransceiver 24 which transmits and receives optical signals. The opticaltransceiver 24 is mounted on a circuit board 26 within an electronicdevice, which is connected upon the optical path. By the optical device25, there are included both a light emitting device and a lightreceiving device. As the light emitting device, it is possible toutilize a so-called surface emission type laser diode (VCSEL: VerticalCavity Surface-Emitting Laser) or the like, and, as the light receivingdevice, it is possible to use a light receiving device such as aphotodiode or the like.

The optical transceiver 24, for example, may be a small element of achip type or an array type, in which the optical device 25 was formed ona mount 24A. In the optical transceiver, the light emitting device orthe light receiving device is an optical input or output terminatorwhich emits or receives incidence of an optical signal.

The optical connector 21 is formed mainly of a connector main body 22,which is shaped as a block like rectangular parallelepiped with groovesformed upon its surface which faces said optical device 25, and whichmay be, for example, made from an epoxy resin material or the like. Theupper surface of the connector main body 22 in FIGS. 7 through 11constitutes the installation surface 22 a which faces the opticaltransceiver 24, and, as shown in FIGS. 13 and 14, the optical connector21 is installed to the optical transceiver 24 by turning it over. Thisconnector main body 22 is almost the same size as, or slightly smallerthan, the optical transceiver 24, and does not greatly extend to theexterior from the transceiver main body 24, thus not occupying space.

The connector main body 22 comprises: a hollow optical fiber holdingportion 28 for holding chiefly the coating portion of an optical fiber23 which is led out in parallel with the circuit board surface 26 a; anoptical fiber aperture 29 which passes and fixes the vicinity of the tipend of the optical fiber 23; and a concave spot 211 for changing theoptical axis, which has a reflective surface for changing the opticalaxis 210, formed forwards along the exit hole of this optical fiberaperture 29, which causes the direction of the optical axis of theoptical fiber 23 to face said optical device 25.

The reflective surface for changing the optical axis 210 is slanted atan angle of 45° with respect to the optical axis direction of theoptical fiber 23 (precisely, with respect to the direction ofprolongation of the optical axis of the tip end surface of the barefibers). When the optical connector 21 is fitted upon the transceivermain body 24, the light emitting surface of the optical device 25, whichis positioned at the upper side of the optical device 25 above thetransceiver main body 24 facing the light receiving surface, bendsthrough an angle of 90 degrees the light emitted from the tip end of theoptical fiber 23 and illuminates it upon the optical device 25, or bendsthrough an angle of 90 degrees the light emitted from the optical deviceand illuminates it upon the optical fiber 23. Although the reflectivesurface for changing the optical axis 210 may be formed upon theslanting wall surface of the concave spot for changing the optical axis211 by metal vapor deposition or the like, it may also be made bycombining a chip upon which such a film has been formed with saidslanting wall surface. Apart from these, any means by which thereflective surface can be formed is optional.

Although the slant angle of the reflective surface for changing theoptical axis 210 is suitably a slant angle of 45° with respect to thedirection of the optical axis of the optical fiber 23, it is notnecessarily limited to being 45°. According to requirements, it would bepossible to utilize any angle which is capable of causing reflection ofthe light which has been emitted from the optical fiber 23 so that itcan enter the optical device 25, or which can cause reflection along apath which is reverse thereto.

The optical connector 21 of this embodiment is one which utilizes acoated optical fiber ribbon. The optical fibers 23 are single-coreoptical fibers constituting the coated optical fiber ribbon 23′, and areUV lines with, for example, an outer diameter of 0.25 mm. In FIGS. 12through 14, 23 a is a bare fiber. The connector main body 22 has aplurality of optical fiber apertures 29 which correspond to thesingle-core optical fibers 23 or the coated optical fiber ribbon 23′,and is provided with a plurality of position determination grooves 212for accurately positioning the optical fibers 23 which are led to eachof the optical fiber apertures 29.

Although the position determination grooves are desirably V-grooves,they are not limited to being such; for example, it would also beacceptable to utilize round grooves (grooves which were semi-circular incross section), or U-grooves or the like.

The hollow optical fiber holding portion 28 is a hollow space portionwhich connects together an optical fiber insertion aperture portion 28 awhich opens in a direction parallel to the installation face 22 a of theconnector main body 22 for the optical transceiver 24 (parallel to thecircuit board surface 26 a), and an adhesive material filling apertureportion 28 b which opens in a direction orthogonal to the circuit boardsurface 26 a (in the example shown in the Figures, it opens to the sideof the installation face 22 a).

Position determination pin holes 214 into which position determinationpins 213 are inserted open to the left and to the right sides of theconcave spot for changing the optical axis 211 of the connector mainbody 22. Dilated portions (i.e., counter sunk portions) are provided atthe opening end portions of the pin holes for position determinationshown in the Figure, in order to make it easy to insert the positiondetermination pins 213. Furthermore, instead of providing the dilatedportions, it would also be acceptable to perform this guiding by taperedsurfaces or radiused surface. Yet further, pin holes 24 a for positiondetermination, which are for allowing the insertion of positiondetermination pins 213, are opened on the side of the opticaltransceiver as well. The position determination pins 213 have a functionof performing accurate position determination for the optical device 25upon the optical transceiver 24 of the connector main body 22, whenfitting into the pin holes for position determination 214 upon theconnector main body 22 side and into the pin holes 24 a for positiondetermination upon the optical transceiver 24 side.

When fitting the optical fibers 23 to the above described connector mainbody 22, each of the single-core optical fibers 23 (e.g., UV elementlines) which constitute the coated optical fiber ribbon 23′ is exposed,and furthermore the coating upon these optical fibers 23 is removed, soas to expose the bare fibers 23 a. Next, the coated optical fiber ribbon23′ is inserted from the optical fiber insertion aperture portion 28 a,and the bare fibers 23 a are inserted into the optical fiber aperture 29while determining the position of each of the optical fibers 23accurately by inserting the optical fibers 23 into the positiondetermination grooves 212. The bare fibers 23 a are slightly projectedout from the exit of the optical fiber aperture 29. Since, in this case,the position determination grooves 212 can be seen from the window (theadhesive material filling aperture portion 28 b), accordingly the tipend vicinities of the optical fibers 23 can be seen as they ride alongthe position determination grooves 212, and each of the optical fibers23 can be reliably guided by visual inspection into the positiondetermination groove which is its respective objective. Next, adhesivematerial 216 is charged into the hollow optical fiber holding portion28, and thereby the optical fibers 23 are fixed together with the coatedoptical fiber ribbon 23′. Furthermore, a transparent adhesive material217 is charged into the concave spot for changing the optical axis 211,and a transparent glass plate 218, which is, for example, made fromresin, is fixed from above so as to cover it. The portion where theglass plate 218 is arranged provides a concave spot 215 for disposingthe thin glass plate, so as to surround the concave spot for changingthe optical axis 211, and this glass plate 218 does not project out fromthe installation surface 22 a of the connector main body 22, andfurthermore is not directly contacted against the optical device 25.

For the transparent adhesive material 217 and the glass plate 218,materials are used which have optical characteristics which do not giverise to any bad influence such as light loss or the like. However, it ispossible to utilize an adhesive material or glass which has the opticalcharacteristic of being transparent with respect to light of a specificwavelength. It is possible to prevent dirt upon the reflective surfacefor changing the optical axis 210 due to the ingress of dust or dirt orthe like by using the adhesive material 217 or the glass plate 218. Theassembly of the optical connector 21 to the tip end of the optical fiber23 is performed by doing as described above.

FIGS. 13 and 14 are figures showing a situation in which the abovedescribed optical connector 21 is being used. The upper surface of theconnector main body 22 in FIGS. 7 through 11 is the installation face 22a which faces the optical transceiver 24. As in FIGS. 13 and 14, whenthe optical connector 21 is turned over, and the position determinationpins 213 are inserted into the pin holes 214 for positionaldetermination, positional determination of the optical connector 21 withrespect to the optical transceiver 24 is performed. Thus, the positionof the reflective surface for changing the optical axis 210 ispositionally determined correctly with respect to the optical device 25of the optical transceiver 24, and the direction of the optical axis ofthe optical fibers 23 (exactly, the optical axis direction of the tipend surfaces of the bare fibers 23 a) is correctly changed to thedirection of the optical devices 25 of the optical transceiver 24. Dueto this, the light which was emitted from the tip end surfaces of theoptical fibers 23 is reflected by the reflective surface for changingthe optical axis 210 and is correctly incident upon the light receivingdevices (the optical devices 25) of the optical transceiver 24; or,alternatively, the light which was emitted by the light emitting devices(the optical devices 25) is reflected by the reflective surface forchanging the optical axis 210 and is correctly incident upon the endsurfaces of the optical fibers 23.

Since, in this manner, with the connector 21 of the present invention,the optical fiber aperture 29 and the reflective surface for changingthe optical axis 210 are provided upon the block shaped unitarycomponent (the connector main body 22), and the mutual positionalrelationship of the optical axis of the optical fibers 23 and thereflective surface for changing the optical axis 210 is fixed at highaccuracy, thereby it is possible to make an optical connection betweenthe optical fibers 23 and the optical devices 25 while reducing thelosses.

Further, the optical connector 21 of the present invention has astructure like one in which the reflective surface for changing theoptical axis is provided integrally with the optical connector ferrulewhich performs the optical connection with the optical fiber, so that itis possible to implement reduction of size easily, and furthermore it isalso easy to avoid interference with the wiring pattern or the like uponthe circuit board 26.

With the present invention, the hollow optical fiber holding portion isnot limited to a hollow optical fiber holding portion 28 like the one ofthe embodiment. For example, it would also be acceptable to utilize ahollow space portion which opened at the opposite side to theinstallation surface 22 a for the connector main body 22. Further, itwould be acceptable to be a hollow space portion having no apertureportion oriented orthogonally to the circuit board surface 26 a.Furthermore, it would be acceptable for it to be a hollow space portionwhich is shaped like a simple concave spot. In short, anything will beacceptable, provided that it is able to maintain a covering over theoptical fibers 23.

Moreover, as the optical fiber which can be attached to the opticalconnector of the present invention, this is not limited to the case of acoated optical fiber ribbon 23′ such as in the embodiment; it would bepossible simply to fix it to a plurality of single-core optical fibers23. Indeed, it would also be possible to fix it to only one single-coreoptical fiber 23. With regard to the structure of the optical fiber 23per se, it is not limited to a case of being a UV line. It would bepossible to utilize various types of structure.

Yet further, if sufficient fixing is not obtained by only inserting theposition determination pins into the pin holes for positiondetermination upon the optical transceiver 24, as in the embodimentdescribed above, it would be possible to employ a fixing means in whicha hole for position determination was opened up in the circuit board aswell, and position determination pins were inserted into the pin holesfor position determination in both of the optical transceiver 24 andalso the circuit board 26. Alternatively, a fixing means in which aconnector holder which was formed, for example, by bending a stainlesssteel plate was attached to the circuit board side separately, and whichheld by this connector holder gripping the optical connector 21, or someother type of fixing means can be employed.

Even further, although, in the embodiment, an optical transceiver 24which was formed as a module upon the circuit board 26 was implemented,it would also be possible to apply the present invention in the case ofproviding an optical device and various types of device or component forimplementing an optical transceiver function upon the circuit board 26.In this case, it would be provided directly upon the circuit board 26,and would face the optical device upon the circuit board 26.

Furthermore, as the optical input and output terminator which isprovided directly or indirectly upon the circuit board, this is notlimited to being an optical device; it would also be possible to utilizevarious types of construction, such as, for example, one in which theend portion of the optical fiber was pulled into and fixed to thecircuit board 26, or the like.

Since, according to the optical connector of this embodiment, theoptical fiber aperture 29 and the reflective surface for changing theoptical axis 210 are provided upon a unitary block shaped component (theconnector main body 22), and the mutual positional relationship of theoptical axis of the optical fibers 23 and the reflective surface forchanging the optical axis 210 is fixed with high accuracy. Thus, it ispossible to implement optical axis change of the optical axis directionof the optical fibers 23 towards the side of the optical device 25 withgood accuracy. Due to this, it is possible to reduce the losses in theoptical connection between the optical fibers 23 and the optical devices25. Further, since the optical fiber aperture 29 and the reflectivesurface for changing the optical axis 210 are provided upon the unitaryblock shaped component, it is thus possible to implement reduction ofsize easily and to easily avoid interference with the wiring pattern orthe like upon the circuit board 26.

It should be understood that, in any of the embodiments, the adhesivematerial is not limited to being an adhesive material which is perfectlytransparent. Even if the adhesive is semi-transparent, it can be used,provided that it allows the light which passes along the optical fiberto pass through it within a permitted transmission factor range.

Further, as shown in FIGS. 5A and 8 and so on, if a multi-core opticalfiber ribbon core is used, a structure will be acceptable in which oneor a plurality of optical fibers which are positioned at one sidethereof in the widthwise direction are used for signal transmission, andone or a plurality of optical fibers which are positioned at the otherside thereof are used for signal reception. Moreover, a structure willbe acceptable in which one or a plurality of fibers at its centralportion in its widthwise direction are not used. In this case, thedistance between the optical signal generation portion and the opticalsignal reception portion becomes greater to the extent that fibers arepresent in the central portion which are not in use, so that it ispossible to reduce the occurrence of problems of signal mixing and thelike due to light scattering yet further.

Furthermore, with the present invention, the connector holder can alsobe implemented with a structure which consists only of an engagementmeans or only of a position determination means.

The position determination pins are so called projecting members whichperform positional determination between the optical connector and thesubstrate. Desirably, as shown by way of example in the embodimentsdescribed above, round cylindrical pins made from a metallic materialare used for these position determination pins, but this is not to beconsidered as being limitative. It would also be acceptable to utilizeprojections which were made by being integrally formed upon an opticalconnector made from a resin material, or projections which were made bybeing integrally formed upon a substrate made from a resin material. Itis possible for such a structure to correspond to the positiondetermination pin of the present invention, provided that it projectsfrom the side of the optical connector or the side of the substratetowards the side of the other, and that it fulfils the function ofperforming positional determination between the optical connector andthe substrate. For example, if a projecting portion which is provided asprojecting upon the optical connector and which fits together with theside of the other (the substrate) fulfils the function of performingpositional determination between the optical connector and thesubstrate, then this projecting portion which is provided as projectingfrom said optical connector may be termed a “position determination pin”according to the present invention. Furthermore, if a projecting portionwhich is provided as projecting upon the side of the substrate fulfilsthe function of performing positional determination between the opticalconnector and the substrate by fitting together with a concave spot (anengagement portion) upon the side of the optical connector, then it maybe termed a “position determination pin” according to the presentinvention. The position determination pin, as described earlier, maydesirably be a round cylindrical pin which has a circular shape in crosssection, but it will also be acceptable for its cross sectional shape tobe, for example, elliptical, rectangular, square, or the like.Furthermore, the cross sectional shape may also be a hollow shape. Yetfurther, although the position determination pins are desirably two innumber, it would also be acceptable, in view of objectives such asenhancing the accuracy of positional determination and the like, forthis number to be different from two (one, or three or more).

On the other hand, the “pin hole” (the “pin hole for positionaldetermination”) in this specification is an expression for the portioninto which the position determination pin fits, and it is not to beconsidered as being limited to a pin hole which is a round aperturewhich corresponds to a round cylindrical pin. If, by fitting togetherwith the position determination pin, any thing determines the positionof this position determination pin at high accuracy, and thus fulfilsthe function of performing positional determination between thesubstrate and the optical connector, then that thing may be termed a pinhole according to the present invention.

INDUSTRIAL APPLICABILITY

According to the present invention, it is possible to reduce the size ofthe construction for fitting the optical connector to the circuit boardupon which the optical device is installed, and, while the opticalconnector is easily fitted upon the circuit board, the designflexibility for its fitting position is enhanced, and moreover theposition determination of the optical connector with respect to theoptical device may be performed easily and moreover accurately.

1. An optical connector, fitted upon the tip end portion of an opticalfiber ribbon where a plurality of optical fibers are disposed with arrayform and disposed to face a plurality of optical input and outputterminators which are installed upon a substrate, and which opticallyconnects between each optical fiber of the optical fiber ribbon and eachoptical input and output terminator, and comprising a block shapedconnector main body which is disposed to face the plurality of opticalinput and output terminators; and wherein the connector main bodycomprises: a hollow optical fiber holding portion for holding mainly acoating portion of each optical fiber which is led generally in parallelwith the surface of the substrate; a plurality of optical fiberapertures into which the tip end vicinity of the plurality of opticalfibers are respectively inserted and fixed; a window of the hollowoptical fiber holding portion for filling an adhesive material; aplurality of position determination grooves for respectively positioningthe plurality of optical fibers, which are respectively led to theplurality of optical fiber apertures, and are seen from the window ofthe hollow optical fiber holding portion; and a concave spot forchanging the optical axis comprising a reflective surface for changingthe optical axis and formed in front of an exit of the plurality ofoptical fiber apertures, which causes the optical axis direction of theoptical fiber to face the plurality of optical input and outputterminators.
 2. The optical connector as claimed in claim 1, wherein thehollow optical fiber holding portion connects together an optical fiberinsertion aperture portion which opens in a direction parallel to thesurface of the substrate, and the adhesive material filling apertureportion.
 3. The optical connector as claimed in claim 1, wherein atransparent or semi-transparent adhesive material is charged into theconcave spot for changing the optical axis, which is covered over by afixed transparent plate.
 4. The optical connector as claimed in claim 1,wherein pin holes for position determination, into which are fittedposition determination pins for performing positional determination withthe substrate side, are provided respectively at both sides of theconnector widthwise direction of the concave spot for changing theoptical axis of the connector main body.
 5. The optical connector asclaimed in claim 1, wherein position determination pins, which fit intopin holes for position determination opened in the substrate side, areprovided respectively at both sides of the connector widthwise directionof the concave spot for changing the optical axis of the connector mainbody.
 6. An optical connector, fitted upon the tip end portion of anoptical fiber ribbon where adjacent optical fibers are densely disposed,and disposed to face a plurality of optical input and output terminatorswhich are installed on a substrate, and which optically connects betweeneach optical fibers of the optical fiber ribbon and each optical inputand output terminator, and comprising a block shaped connector main bodywhich is disposed to face the plurality of optical input and outputterminators; and wherein the connector main body comprises: a hollowoptical fiber holding portion for holding mainly a coating portion ofeach optical fibers which are led generally in parallel with the surfaceof the substrate; a plurality of optical fiber apertures into which thetip end vicinity of the plurality of optical fibers are respectivelyinserted and fixed; a window of the hollow optical fiber holding portionfor filling an adhesive material; a plurality of position determinationgrooves for respectively positioning the plurality of optical fiberswhich are respectively led to the plurality of optical fiber aperturesand are seen from the window of the hollow optical fiber holdingportion; and a concave spot for changing the optical axis comprising areflective surface for changing the optical axis and formed in front ofan exit of the plurality of optical fiber apertures, which causes theoptical axis direction of the optical fiber to face the plurality ofoptical input and output terminators.
 7. The optical connector asclaimed in claim 6, wherein the hollow optical fiber holding portionconnects an optical fiber insertion aperture portion which opens in adirection parallel to the surface of the substrate and the adhesivematerial filling aperture portion.
 8. A optical connector as claimed inclaim 6, wherein a transparent or semi-transparent adhesive material ischarged into the concave spot for changing the optical axis, which iscovered over by a fixed transparent plate.
 9. The optical connector asclaimed in claim 6, wherein pin holes for position determination, intowhich position determination pins are fitted for performing positionaldetermination with the substrate side, are provided respectively at bothsides of the connector widthwise direction of the concave spot forchanging the optical axis of the connector main body.
 10. The opticalconnector as claimed in claim 6, wherein position determination pins,which fit into pin holes for position determination opened in thesubstrate side, are provided at both sides of the connector widthwisedirection of the concave spot for changing the optical axis of theconnector main body.